Droperidol is effective for PONV prophylaxis. Its antiemetic action is primarily mediated by antagonism of which receptor?

• A Serotonin 5-HT3 receptor
• B Muscarinic acetylcholine receptor
• C Dopamine D2 receptor ✓
• D Neurokinin-1 receptor

Explanation

Droperidol is a butyrophenone that exerts its antiemetic effect by blocking dopamine D2 receptors in the chemoreceptor trigger zone (area postrema). It is effective at low doses (0.625-1.25 mg). It carries a black box warning for QT prolongation. 5-HT3 antagonism is the mechanism of ondansetron; muscarinic antagonism is scopolamine; NK1 antagonism is aprepitant.

Reference: Katzung and Trevor's Basic and Clinical Pharmacology, 15th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

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